High School Introduction to Special Relativity

Summary of the In Orbit topic.

The history of the understanding of light from antiquity to the beginning of the 20th century. 

NSW HSC Physics Syllabus 9.2.4

‘Current and emerging understanding about time and space has been dependent upon earlier models of the transmission of light.’

Outline of the Aether theory of light.

Description of the apparatus and experimental method used by Michelson and Morley, the results of their experiment to measure the Aether Wind, and the consequences of their failure to detect any evidence for the Aether.

NSW HSC Physics Syllabus 9.2.4.2.1

‘Outline the features of the aether model for the transmission of light.’

NSW HSC Physics Syllabus 9.2.4.2.2

‘Describe and evaluate the Michelson- Morley attempt to measure the relative velocity of the Earth through the aether.’

NSW HSC Physics Syllabus 9.2.4.2.3

‘Discuss the role of the Michelson- Morley experiments in making determinations about competing theories.’

NSW HSC Physics Syllabus 9.2.4.3.1

‘Gather and process information to interpret the results of the Michelson- Morley experiment.’ 

The Principle of Relativity and the ideas of Galileo.

NSW HSC Physics Syllabus 9.2.4.2.4

‘Outline the nature of inertial frames of reference.’

NSW HSC Physics Syllabus 9.2.4.2.5

‘Discuss the principle of relativity.’ 

Inertial and non-inertial frames of reference and the principle of relativity.

See previous lecture for resources.

NSW HSC Physics Syllabus 9.2.4.2.4

‘Outline the nature of inertial frames of reference.’

NSW HSC Physics Syllabus 9.2.4.2.5

‘Discuss the principle of relativity.’ 

Einstein's theory of Special Relativity discussed, together with some of his early thought experiments.

The importance of the constancy of c in terms of time, length and mass, 

Einstein's thought experiment underlying the relativity of simultaneity and the relativity of simultaneity discussed.

NSW HSC Physics Syllabus 9.2.4.2.6  

‘Describe the significance of Einstein’s assumption of the constancy of the speed of light.’  

NSW HSC Physics Syllabus 9.2.4.2.7  

identify that if c is constant then space and time become relative  

NSW HSC Physics Syllabus 9.2.4.2.8  

explain qualitatively and quantitatively the consequence of special relativity in relation to:  

– the relativity of simultaneity  

 NSW HSC Physics Syllabus 9.2.4.3.3

analyse and interpret some of Einstein’s thought experiments involving mirrors and trains and discuss the relationship between thought and reality  

Note:  This video contains a fairly obvious edit.  In response to a question I re-recorded the section on simultaneity to make it clearer.

Calculating time dilation.

The formula and thought experiments underlying time dilation discussed.

NSW HSC Physics Syllabus 9.2.4.2.7  

'Identify that if c is constant then space and time become relative.'

NSW HSC Physics Syllabus 9.2.4.2.9

Explain qualitatively and quantitatively the consequence of special relativity in relation to:  

– time dilation  

 NSW HSC Physics Syllabus 9.2.4.3.3

'Analyse and interpret some of Einstein’s thought experiments involving mirrors and trains and discuss the relationship between thought and reality.'

NSW HSC Physics Syllabus 9.2.4.3.5  

‘Solve problems and analyse information using the appropriate formulae.’

See notes for last lecture 'Special Relativity and Simultaneity' for notes and worked examples for this lecture.

Calculating length contraction.

The formula for length contraction and the underlying thought experiment discussed.

NSW HSC Physics Syllabus 9.2.4.2.7

‘Identify that if c is constant then space and time become relative.’

  NSW HSC Physics Syllabus 9.2.4.2.8

 ‘Discuss the concept that length standards are defined in terms of time in contrast to the original meter standard.’

NSW HSC Physics Syllabus 9.2.4.2.9

Explain qualitatively and quantitatively the consequence of special relativity in relation to:

– length contraction 

NSW HSC Physics Syllabus 9.2.4.3.5

‘Solve problems and analyse information using the appropriate formulae.’ 

Relativistic mass and the equivalence of mass and energy, and how to calculate both.

Discussion of a thought experiment explaining relativistic mass.

Discussion of the equivalence of mass and energy.

NSW HSC Physics Syllabus 9.2.4.2.6

‘Describe the significance of Einstein’s assumption of the constancy of the speed of light.’

NSW HSC Physics Syllabus 9.2.4.2.9

Explain qualitatively and quantitatively the consequence of special relativity in relation to:

– the equivalence between mass and energy

– mass dilation 

NSW HSC Physics Syllabus 9.2.4.3.5

‘Solve problems and analyse information using the appropriate formulae.’ 

Discussion of the nature of thought experiments and the discovery of evidence supporting Einstein's theories.

Discussion of the impact of relativity on Space Travel.

NSW HSC Physics Syllabus 9.2.4.3.4

‘Analyse information to discuss the relationship between theory and the evidence supporting it, using Einstein’s predictions based on relativity that were made many years before evidence was available to support it.’

NSW HSC Physics Syllabus 9.2.4.2.10

‘Discuss the implications of mass increase, time dilation and length contraction for space travel.’

See previous lecture for printable notes.

Summary of the Relativity topic.